feat: 重构前后端架构，添加Go后端和Python Agent服务

- 新增 Go 语言后端服务(server/)，包含用户认证、Agent管理、数据库连接等API
- 新增 Python Agent 服务(agent/)，实现Agent核心逻辑和工具集
- 前端从原生HTML迁移到Vue.js框架(web/src/)
- 添加 Docker Compose 支持(docker-compose.yml)
- 添加项目架构文档(docs/ARCHITECTURE.md)
- 添加环境变量示例(.env.example)和本地启动脚本(start-local.ps1)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/internal/repository/audit_repo.go

@@ -0,0 +1,56 @@
+package repository
+
+import (
+	"x-agents/server/internal/model"
+
+	"gorm.io/gorm"
+)
+
+type AuditRepository struct {
+	db *gorm.DB
+}
+
+func NewAuditRepository(db *gorm.DB) *AuditRepository {
+	return &AuditRepository{db: db}
+}
+
+func (r *AuditRepository) Create(log *model.AuditLog) error {
+	return r.db.Create(log).Error
+}
+
+func (r *AuditRepository) FindByUserID(userID string, limit int) ([]model.AuditLog, error) {
+	var logs []model.AuditLog
+	err := r.db.Where("user_id = ?", userID).Order("created_at DESC").Limit(limit).Find(&logs).Error
+	return logs, err
+}
+
+func (r *AuditRepository) FindByAgentID(agentID string, limit int) ([]model.AuditLog, error) {
+	var logs []model.AuditLog
+	err := r.db.Where("agent_id = ?", agentID).Order("created_at DESC").Limit(limit).Find(&logs).Error
+	return logs, err
+}
+
+// ToolApproval 工具审批仓储
+
+func (r *AuditRepository) CreateApproval(req *model.ToolApprovalRequest) error {
+	return r.db.Create(req).Error
+}
+
+func (r *AuditRepository) FindApprovalByID(id string) (*model.ToolApprovalRequest, error) {
+	var req model.ToolApprovalRequest
+	err := r.db.First(&req, "id = ?", id).Error
+	if err != nil {
+		return nil, err
+	}
+	return &req, nil
+}
+
+func (r *AuditRepository) FindPendingApprovals() ([]model.ToolApprovalRequest, error) {
+	var reqs []model.ToolApprovalRequest
+	err := r.db.Where("status = ?", model.ApprovalStatusPending).Order("created_at ASC").Find(&reqs).Error
+	return reqs, err
+}
+
+func (r *AuditRepository) UpdateApproval(req *model.ToolApprovalRequest) error {
+	return r.db.Save(req).Error
+}